Hexapods work very simply -- the front and rear
legs on a given side are connected, and are driven
together by one motor (per side). The middle legs
are used to shift the 'bot's weight from side to
side (thus selecting the leg pair in use at a given
time). This is easiest to visualize with a quick
(and if it's enabled), you can use the animation
panel to the right to step through the geometry (or
just hit "play" and watch it walk).
Here, the right side front / back legs (along
with the left middle leg) are drawn in green; the
left front / back legs (along with the right middle
leg) are in red. The 'bot body is denoted by the
black outlined rectangle, the feet are solid if
they are load bearing (i.e., are touching the
ground), and unfilled if they are not supporting
Turning is accomplished by changing the angle
through which the legs on a given side "reach"
forward in a given cycle.